Cosmic ray produced Radioisotopes for studying the General Circulation in the atmosphere

The possibility of using cosmic ray produced radioisotopes for studying large scale circulation in the atmosphere has been explored recently. The potential significance of these isotopes in the field of metrology arises because of the following features in their production and properties-(l) Several radioisotopes are available whose half-lives are comparable to time scales involved in the atmospheric circulation. Four of the isotopes (S35, Be7, P33, and P32) have half-life periods ranging from three months to a fortnight, and one (Na22) has a half-life of about two and a half years, and (2) Isotope production is continuous, constant, strongly dependent on the latitude and altitude in the atmosphere and independent of meteorological factors, These isotopes can be used for investigating the nature of circulation of air in the troposphere and the detailed mechanism of exchange of air between the stratosphere and the troposphere. Experimental work on the use of these isotopes in meteorology has so far been confined mainly to determination of the concentration in rainwater by the Geophysics Research Group of the Tata Institute of Fundamental Research, Bombay. Some of the important results of these investigations are summarized in this pa per.

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Dating of Polar Ice By 32Si

Journal of Glaciology ◽

10.3189/s0022143000031828 ◽

1973 ◽

Vol 12 (66) ◽

pp. 411-416 ◽

Cited By ~ 2

Author(s):

Henrik B. Clausen

Keyword(s):

Half Life ◽

Specific Activity ◽

Greenland Ice Sheet ◽

Cosmic Ray ◽

Polar Ice ◽

Poor Knowledge ◽

The Poor ◽

Glacier Ice ◽

Cosmic Ray Flux

32Si dating of glacier ice has hitherto been complicated by the poor knowledge of the half life. Furthermore, fall-out of bomb-produced 32Si impedes the determination of the specific activity of cosmic-ray produced 32Si in recent precipitation. Measurements on well-dated pre-bomb samples from the Greenland ice sheet establish a calibration for 32Si dating of up to 1 000 year old polar ice samples of the magnitude of 1 metric ton. If the technique is used on temperate glaciers, samples of pre-bomb deposits (or from after 1970) must be collected for comparison with samples of old ice, using an apparent half life of 295±25 years. Due to secular cosmic-ray flux variations, the true half life of 32Si is estimated at the slightly higher value of 330±40 years.

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Dating of Polar Ice By 32Si

Journal of Glaciology ◽

10.1017/s0022143000031828 ◽

1973 ◽

Vol 12 (66) ◽

pp. 411-416 ◽

Cited By ~ 47

Author(s):

Henrik B. Clausen

Keyword(s):

Half Life ◽

Specific Activity ◽

Greenland Ice Sheet ◽

Cosmic Ray ◽

Polar Ice ◽

Poor Knowledge ◽

The Poor ◽

Glacier Ice ◽

Cosmic Ray Flux

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Book reviews: A magnificent obsession

Notes and Records the Royal Society journal of the history of science ◽

10.1098/rsnr.1996.0035 ◽

1996 ◽

Vol 50 (2) ◽

pp. 265-266

Keyword(s):

Cosmic Rays ◽

Small Group ◽

Nuclear Energy ◽

Cosmic Ray ◽

Atomic Energy ◽

Neutrino Experiment ◽

Homi Bhabha ◽

Tata Institute ◽

Fundamental Research

G. Venkataraman, Bhabha and his Magnificent Obsession Vignettes in Physics, Sangam Books, London, 1994. £6.95 (Paperback) ISBN 0 86311 555 1 On 22nd January, 1966, Homi Bhabha addressed a vast gathering at the Atomic Energy Establishment in Trombay - held to offer condolences on the death of President Lai Bahadur Shastri. The following day Bhabha’s Air India plane crashed into Mont Blanc as it commenced its descent into Geneva airport. Thus perished one of India’s most gifted scientists and a man who was a scholar in other fields too. It is ironic that the following day the present reviewer addressed a small group of heart-broken Indian physicists at the site of their joint cosmic ray neutrino experiment in the Kolar Gold Fields. Venkataram has written a fine book about his countryman, chronicling his early work in Cambridge and elsewhere on cosmic rays, not least the theory underlying their behaviour, his great legacy - the Tata Institute of Fundamental Research (TIFR) in Bombay - and the development of Nuclear Energy in India.

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Large-scale Motion of Solar Filaments

International Astronomical Union Colloquium ◽

10.1017/s0252921100064502 ◽

2000 ◽

Vol 179 ◽

pp. 205-208

Author(s):

Pavel Ambrož ◽

Alfred Schroll

Keyword(s):

Magnetic Flux ◽

Proper Motion ◽

Time Scale ◽

Large Scale ◽

Accuracy Of Measurements ◽

Solar Filaments ◽

General Movement ◽

Scale Motion ◽

Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

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Methods for the Quantification of Salivary Cortisol and of a-amylase in Biosensors and Portable Devices

Revista de Chimie ◽

10.37358/rc.17.12.5994 ◽

2018 ◽

Vol 68 (12) ◽

pp. 2857-2859

Author(s):

Cristina Mihaela Ghiciuc ◽

Andreea Silvana Szalontay ◽

Luminita Radulescu ◽

Sebastian Cozma ◽

Catalina Elena Lupusoru ◽

...

Keyword(s):

Real Time ◽

Medical Practice ◽

Salivary Cortisol ◽

Clinical Studies ◽

Large Scale ◽

Psychological Research ◽

Portable Devices ◽

Salivary Amylase ◽

Specificity And Sensitivity

There is an increasing interest in the analysis of salivary biomarkers for medical practice. The objective of this article was to identify the specificity and sensitivity of quantification methods used in biosensors or portable devices for the determination of salivary cortisol and salivary a-amylase. There are no biosensors and portable devices for salivary amylase and cortisol that are used on a large scale in clinical studies. These devices would be useful in assessing more real-time psychological research in the future.

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Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207322666190412165316 ◽

2019 ◽

Vol 22 (5) ◽

pp. 346-354

Author(s):

Yan A. Ivanenkov ◽

Renat S. Yamidanov ◽

Ilya A. Osterman ◽

Petr V. Sergiev ◽

Vladimir A. Aladinskiy ◽

...

Keyword(s):

Antibacterial Activity ◽

Large Scale ◽

Underlying Mechanism ◽

Luciferase Assay ◽

Reporter System ◽

E Coli ◽

Starting Point ◽

High Concentrations ◽

Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

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Determination of the confining effect of geogrid rein-forcement from large scale triaxial tests

Can Tho University Journal of Science ◽

10.22144/ctu.jen.2016.037 ◽

2016 ◽

Vol 04 ◽

pp. 6

Author(s):

Thang, H.V.

Keyword(s):

Large Scale ◽

Triaxial Tests ◽

Confining Effect

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CNN-Based Classifier as an Offline Trigger for the CREDO Experiment

Sensors ◽

10.3390/s21144804 ◽

2021 ◽

Vol 21 (14) ◽

pp. 4804

Author(s):

Marcin Piekarczyk ◽

Olaf Bar ◽

Łukasz Bibrzycki ◽

Michał Niedźwiecki ◽

Krzysztof Rzecki ◽

...

Keyword(s):

Wavelet Transforms ◽

Exploratory Study ◽

Large Scale ◽

Morphological Difference ◽

Cosmic Ray ◽

Input Image ◽

Image Features ◽

The Earth ◽

Cmos Sensor ◽

Competition Process

Gamification is known to enhance users’ participation in education and research projects that follow the citizen science paradigm. The Cosmic Ray Extremely Distributed Observatory (CREDO) experiment is designed for the large-scale study of various radiation forms that continuously reach the Earth from space, collectively known as cosmic rays. The CREDO Detector app relies on a network of involved users and is now working worldwide across phones and other CMOS sensor-equipped devices. To broaden the user base and activate current users, CREDO extensively uses the gamification solutions like the periodical Particle Hunters Competition. However, the adverse effect of gamification is that the number of artefacts, i.e., signals unrelated to cosmic ray detection or openly related to cheating, substantially increases. To tag the artefacts appearing in the CREDO database we propose the method based on machine learning. The approach involves training the Convolutional Neural Network (CNN) to recognise the morphological difference between signals and artefacts. As a result we obtain the CNN-based trigger which is able to mimic the signal vs. artefact assignments of human annotators as closely as possible. To enhance the method, the input image signal is adaptively thresholded and then transformed using Daubechies wavelets. In this exploratory study, we use wavelet transforms to amplify distinctive image features. As a result, we obtain a very good recognition ratio of almost 99% for both signal and artefacts. The proposed solution allows eliminating the manual supervision of the competition process.

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